Electroproduction of omega (783) mesons using CLAS at Jefferson Lab
Electroproduction of omega(783) mesons from a proton target has been measured in a search for so called “missing baryon resonances”. A 4.0 GeV electron beam was used. The scattered electrons were measured in coincidence with the recoiling proton and the positive pion from the omega decay. Missing mass techniques were applied to identify the omega in the final state, and to reduce the rho(770) contribution. The data show the omega very clearly on a smooth background originating predominantly from three-pion phase space. Yields have been extracted, and the W and t dependencies determined. The t dependence is mostly monotonic for W > 2 GeV, as expected from pion-exchange and diffractive processes, while for W < 2 GeV strongly non-monotonic behavior is observed, indicative of possible s-channel nucleon resonance contributions.